High voltage circuit breaker comprising a mechanical linkage interconnecting its components for synchronized operation thereof

ABSTRACT

A circuit breaker comprising spaced-apart, high voltage enclosures respectively mounted atop spaced-apart insulators, circuit interrupters within the enclosures, and control valves respectively associated with the interrupters for controlling their operation. The control valves are interconnected by a mechanical linkage for simultaneously operating the control valves. The linkage comprises a force-equalizing coupling, the parts of which can change position slightly in response to minor shifting of one enclosure relative to another without imparting motion through said linkage to any of said control valves.

United States Patent [72] Inventors PhilipBarkan Media; PhilipSciscione, Havertown; Edward J. Tuohy, Swarthmore, Pa.

[21] Appl. No. 705,044

[22] Filed Feb. 13, 1968 [45] Patented Feb. 23, 1971 [73] AssigneeGeneral Electric Company [54] HIGH VOLTAGE CIRCUIT BREAKER COMPRISING AMECHANICAL LINKAGE INTERCONNECTING ITS COMPONENTS FOR SYNCHRONIZEDOPERATION THEREOF 17 Claims, 8 Drawing Figs.

[52] U.S. Cl 200/48, 200/145, 200/153, 200/148' [51] Int. Cl. ..H0lh33/02, H01h 33/30 [50] Field of Search 200/ 148.6, 153.7, 153.8, 145,148, 144.2 (Cursory), 48 (Cursory) [56] References Cited UNITED STATESPATENTS 3,167,630 I/ 1965 Alderman et al. 200/48 CIRCUIT BREAKER2,783,338 2/1957 Beatty 200/148 2,979,591 4/1961 Friedrich 200/145X3,300,609 1/1967 Flurscheim et a1. 200/ 145 3,333,071 7/1967 Oppel etal. 200/148X 3,418,439 12/1968 Casey et al.... ZOO/145x FOREIGN PATENTS1,225,268 9/1966 Germany 200/ 148 1,247,452 10/1960 France ZOO/148(6)Primary Examiner-Robert K. Schaefer Assistant ExaminerRobert A.Vanderhye Attorneys-J. Wesley Haubner, William Freedman, Frank L.

Neuhauser and Oscar B. Waddell ABSTRACT: A circuit breaker comprisingspaced-apart, high voltage enclosures respectively mounted atopspaced-apart insulators, circuit interrupters within the enclosures, andcontrol valves respectively associated with the interrupters forcontrolling their operation. The control valves are interconnected by amechanical linkage for simultaneously operating the control valves. Thelinkage comprises a force-equalizing coupling, the parts of which canchange position slightly in response to minor shifting of one enclosurerelative to another without imparting motion through said linkage to anyof said control valves.

PATENTED FEB2 3197:

SHEET 5 OF 5 INVENTORS PHIL/P dc/sc/o/v PHIL/P BAR/(AN,

EDWARD J 700/,

ATTOR/VL'Y BACKGROUND OF THE INVENTION This invention relates to anelectric circuit breaker of the type which comprises a plurality ofwidely spaced interrupting units and, more particularly, relates tomeans for effecting substantially simultaneous operation of saidinterrupting units.

An example of the type of circuit breaker we are concerned with isdisclosed and claimed in US. Pat. No. 2,783,338 to Beatty, assigned tothe assignee of the present invention. This circuit breaker comprises anenclosure at a high voltage with respect to ground, an interrupting unitwithin the enclosure, and a two-position control valve within theenclosure that can be operated from one position to its other positionto effect opening of the interrupting unitand can be returned to saidone position to effect closing of the interrupting unit. A completecircuit breaker typically comprises a plurality of such interruptingunits, each within its own enclosure and each provided with its owncontrol valve. Typically, the individual interrupting units with theirassociated control valves are widely spaced from each other.

In many circuit breaker applications, the individual interrupting unitsare required to operate substantially simultaneously. One way ofeffecting such simultaneous operation is by coupling all the controlvalves together with a long mechanical linkage extending between thewidely spaced control valve locations. A problem encountered when such alinkage is used is that a minor change in the position'of one enclosurewith respect to another tends to produce undesired operation of theinterconnected control valves. Such minor changes in enclosure positioncan result from wind loads, thermal expansion, or unequal settling. Thissame problem of erroneous operation can result from a change in theeffective length of the linkage, due, for example, to' thermal expansionor contraction. Reference may be had to US. Pat. No. 3,350,519 to Badsyet al., assigned to the assignee of the present invention, for a furtherdiscussion of this problem.

SUMMARY An object of our invention is to construct the interconnectinglinkage in such a manner that undesired control valve operation isprevented despite minor changes in the relative positions of theenclosures and despite minor changes in the effective length of thelinkage. I

Another object is to assure that an operating force applied to thelinkage will operate the control valves substantially simultaneouslydespite prior minor changes in the effective length of theinterconnecting linkage and despite prior minor changes in the relativepositions of the enclosures.

Still another object is to maintainthe control valve ends of the linkagein precise positions despite changes in the effective length of thelinkage, yet without introducing lost motion into the linkage andwithout causing the linkage to deform to accommodate the changes inlength. Avoiding such lost motion and deformation is important ifsubstantially simultaneous operation of the control valves is tobe'achieve Still another object is to locate the control valve ends ofthe linkage in precise positions without requiring a high degree ofprecision in assembling the linkage and in locating the enclosures.

Still another object is to construct the linkage in such a manner thatan operating force applied to its driving end will be distributedsubstantially equally between the control valves, despite priorcompensatory action of the linkage to accommodate changes in effectivelength.

In carrying out our invention in one form, we provide a plurality ofspaced-apart high voltage enclosures respectively cuit interrupters arerespectively located within said enclosures, and a plurality of controlvalves respectively located adjacent said plurality of circuitinterrupters are provided for controlling their operation. Common tosaid control valves 5 and located in a position therebetween, we providea force- 7 FIG. 6.

equalizing member which is mechanically connected to the control valvesthrough linkage means. The force-equalizing member is so mounted thatits position can change slightly in response to minor shifting of one ofsaid enclosures relative to another without imparting motion throughsaid linkage means to any of said control valves. An operating rod ismechanically connected at one end of said force-equalizing member and atits other end to motive means capable of applying an operating forcethereto. The motive means permits minor longitudinal movement of the rodin response to a slight change in the position of said force-equalizingmember. The connection between the operating rod and theforce-equalizing member is at a central location on the force-equalizingmember spaced substantially equidistant from the points at which saidlinkage means are connected to said force-equalizing member.

BRIEF DESCRIPTION OF DRAWINGS For a better understanding of theinvention, reference may be had to the following description taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a circuit breaker assemblyembodying one form of our invention.

FIG. la is a schematic illustration 'of part of the circuit breaker ofFIG. 1 including as a portion a sectional view along the line la -la ofFIG. 1. In this FIG. the circuit breaker is shown in its open position.

FIG. 2 comprises a similar sectional view of the circuit breaker of FIG.I but showing the circuit breaker in its closed position. FIG. 2additionally comprises a sectional view of a portion of the circuitbreaker of FIG. 1 taken in a plane parallel to the paper in FIG. 1.

FIG. 3 is a side elevational view of a circuit breaker assemblyembodying a modified form of our invention.

FIG. 4 is a side elevational view partly in section of the circuitbreaker of FIG. 3.

FIG. 5 is a sectional view along the line 5-5 of FIG. 4.

FIG. 6 is a perspective view of a portion of the linkage shown in FIGS.4 and 5.

FIG. 7 is a diagrammatic plan view of the linkage portion of DESCRIPTIONOF PREFERRED EMBODIMENTS Two-Control-Valve Embodiment of FIGS. 1-2

Referring now to FIG. 1, there is shown a high voltage circuit breakercomprising two substantially identical circuit breaker units 11a and 11bconnected in series in a power circuit 25. Each circuit breaker unitcomprises a metal tank 14 at a high voltage with respect to ground andan insulating column 15 supporting the metal tank and electricallyisolating it from ground. A flexible conductor 25a electricallyinterconnects mounted on spaced-apart insulators in such a manner as tothe two circuit breaker units Ila and 11b and does not interfere withthe above-described minor shifting of one circuit breaker unit relativeto the other in'response to such factors as wind loads or unequalsettling. Disposed within each tank 14 is a an interrupting unit of anysuitable type, for example, of the type shown and claimed in theaforesaid U.S. Pat. No. 2,783,338 to Beany: Since the details of theinterrupting unit form no part of the present invention, most of themare not shown. In FIG. la and 2, a block 20 has been used to denote theoperating mechanism of the illustrated interrupting unit.

Each interrupting unit comprises two pairs of relatively movablecontacts 21, 22 and 23, 24 connected in series in power circuit 25extending therethrough. The stationary contact of each pair of contactsis supported on the conductive stud of a terminal bushing 26 projectinginto tank 14. The bushing electrically isolates the stationary contactfrom the tank 14 when the contacts are opened, as shown in FIG. 1. Themovable contact of these pairs of contacts is connected to the commonoperating mechanism by links schematically designated 27 in FIG. in.when operating mechanism 20 operates during a closing operation, itdrives movable contacts 21 and 23 into closed position substantiallysimultaneously. During an opening operation, mechanism 20 drivescontacts 21 and 23 into their open positionsubstantially simultaneously.

Tank 14 contains a high pressure gas, and this is used for operating themechanism 20. For controlling mechanism 20, a control valve 30, shown insimplified schematic form in FIGS. la and 2, is provided in a controlconduit32 interconnecting the pressurized interior of tank 14andoperating mechanism 20. This control valve 30 comprises amovable valveelement 34 that is movable between two positions, one of which is shownin FIG. la and the other in FIG. 2; When in the position of FIG. 1a, thevalve element .34 permits communication between the interior of tank 14and conduit 32 via an inlet port 33 in the valve housing 36. In theposition of FIG. la, the movable valve element 34 also abuts against aseat 37 at the upper end of the valve housing and thus preventspressurized fluid from flowing into a vent passage38 from either thetank 14 or operating mechanism 20. When movable valve element 34 isoperated into its position of FIG. 2, it abuts against the seal 39 andthus blocks communication between the interior tank 14 and operatingmechanism 20. When valve element 34 is in this position of FIG. 2, avent port 41 affords communication between vent passage 38 and controlconduit 32,- thus venting operating mechanism 20.

When control valve 30 is in its'open position of FIG. 1a, operatingmechanism 20 is under pressure and thus holds the contacts open in themanner shown inthe aforesaid Beatty patent. When control valve 30 isoperated to its position of FIG. 2, operating mechanism 20 is vented,and suitable biasing means operates the contacts to their. closedposition in the manner disclosed in the aforesaid Bea'tty patent.

As pointed out hereinabove, we are concerned with the type of circuitbreaker in which widely spaced interruptingunits are required to operatesubstantially simultaneously. For example in the illustrated circuitbreaker, ,the interrupting units in the series-connected circuit breakerunits 11a and 11b are required to operate substantially simultaneously,both during circuit-breaker-opening and during.J'circuit-breakereclosing.

For effecting the desired simultaneous operation of the operating units,we interconnect the movable control valve elements 34 by means of alinkage 40.. This linkage 40 comprises four basic portions: l a linkageportion 40a connected the control valve in circuit breaker unitl Ia andextending between this control valve and a centrally-disposed casing 42;

(2) a substantially identical linkageportion 40b connected to thecontrol valve in circuit breaker unit llb and extending between thiscontrol valve and a centrally-disposed casing 42;

(3) a force-equalizing coupling 44 joining linkage portions 40a and 40btogether; and (4) a vertically-extending operating rod 46 extendingbetween the force-equalizing coupling 44 and a fluid motor 48 at thelower end of the operating rod.

Referring to FIG. 2, this linkageis enclosed by a T- shaped housing 47which comprises major components of insulating material. This T-shapedhousing 47 comprises a vertically extending tubular insulating column148 surrounding vertical operating rod 46 and a metal casing 42 mountedatop column 148. Projecting horizontally-from casing 42 are two tubularsubhousings 49a and 49b, primarily of insulating material, whichsurround linkage portions 40a and 40b, respectively. Each of thesetubular subhousings communicates at one end with the central casing 42and at its other end with the interior of associated tank 14. Theinterior of the T-shaped housing 47 is therefore filled with gas at thesame pressure as the gas inside tanks 14. Certain features of thishousing 47 are described in more detail and claimed in application Ser.No.

705,040 of Sciscione, filed Feb. 15, 1968, now U.S.Pat. No.

Referring to FIGS. la and 2, the linkage portion 400 comprises a valueactuating rod 50a, a first bellcrank 510, an insulating tie rod 52a, asecond bellcrank 54a, and a tie link 55a. The first bellcrank 51a ismounted on a stationary pivot 53a carried by tank 14 and a secondbellcrank 54a is mounted on a stationary pivot 56a carried by centralcasing 42. The valve actuating rod 501: is suitably connectedjat one ofits ends to the movable valve element 34 and at its other end to one armof the first bellcrank 51a. Insulating tie rod 52a is pivotallyconnected at its respective opposite ends to the other end of the firstbellcrank 51a and to one arm of second bellcrank 54a. The other arm ofbellcrank 54a is pivotally connected to the upper end oftie link 55a.

Since the other linkage portion 40b is substantially identical to 40a,it will not be described; but corresponding parts thereof are designatedwith reference numerals corresponding to those used on linkage 40a,except with the suffix b instead of a. I

As shown in FIG. 2, the two linkage portions 40a and 40b are connectedtogether by means .of a force-equalizing coupling 44. This couplingcomprises'a floating force-equalizing member 60 to which the verticaloperating rod 46 is pivotally connected at a centrally-disposed location61. The linkage portions 40a and 40b are pivotally connected to theforce-equalizing member 60 at points 62 and 64 spaced equidistant fromthe operating ro'd connection at 61. The operation of force-equalizingcoupling 44 is explained in greater detail hereinatter, and it will beapparent from such explanation that the force-equalizing member 60 is arigid member that during circuit breaker operation maintains a fixedspacing between points 62 and 64.

Vertical operating rod 46 extends between force-equalizing coupling 44and a fluid motor 48 at its lower end. This operatingrod 46 is, for themost part, form'edof a high strength insulating material.

Fluid motor 48 comprises a piston 70fixed to the lower end 'of operatingrod 46 and slidably mounted in an operating rod 74 extending downwardlytherefrom through an opening 75 in the lower end wall of cylinder 72.Extension rod'74 is slidably mounted in opening 75, and a suitable sealsurrounds rod 74 to prevent leakage through opening 75. Extension 74 isexposed to the surrounding atmosphere at its lower end, thus reducingthe effective area of the lowerface of piston 70 by an amount equal tothe cross-sectional area of opening 75.

Since T-shaped housing 47 is filled with pressurized gas, it

will be apparent that there is always a fluid pressure force actingdownwardly on piston 70. This downward force is present even if equalpressures are presenton opposite sides of piston 70 in view of thepiston's smaller effective area on its lower face than on its upperface. I

For controlling the position of piston 70, a 3way main con trol valve(FIG. 2) is provided. When the circuit breaker is in its closed positionof FIG. 2, the-space beneath piston 70 is vented to atmosphere throughvalve 80.. But when-valve 80 is operated into its dotted line position,thevent to atmosphere is closed, and high pressure gas flows through asupply line 82 into the cylinder space beneath piston 70. Preferably,this pressurized gas is obtained from a source that is at the samepressure as the gas in housing 47.

cmcurr BREAKER OPENING A circuit-breaker-opening operation is initiatedby operating main control valve 80 from itssolid line to its dotted linethe high pressure gas in tank 14 acting against the lower surface 83 ofthe movable valve element 34. This force urges movable valve element 34toward its position of FIG. la, but such motion is prevented when thecircuit breaker is closed by the downward force normally acting onpiston 70. When this downward downward is reduced, as above-described,the fluid pressure force on the movable valve elements 34 is able topredominate and drive the'movable elements. 34 from their position ofFIG. 2 to that of FIG. lag-This opens the circuit breaker as wasdescribed hereinabove.

cmcurr BREAKER ctosmo Circuit-breaker closing from the open position ofFIG. 1a is effected by reversely operating main control valve 80 to ventthe space beneath piston 70. This rapidly increases the net force actingdownwardly on piston 70, thereby driving piston 70 and operating rod 46downwardly. Thismotion is transmitted through force-equalizing member 60and linkages 40a, 40b to movable control valve elements 34. This drivesmovable valve elements 34 downwardly from the position of FIG. In to theposition of FIG. 2. This valve movement vents the operating mechanism20, as previously explained, thus causing it to close the contacts 21,23, as desired.

EQUAL DISTRIBUTION OF CLOSlNG CONTROL FORCE BETWEEN VALVE ELEMENTS Weare able to achieve closely. synchronized movement of the movable valveelements 34 downwardly through their circuit-breaker-closing controlstroke because we distribute the operating from the fluid motor 48substantially equally to the movable valve elements 34. Coupling 44 isable to distribute the downward force from fluid motor-48 substantiallyequally between the two connecting linkages40a and 40b because,referring to the force-equalizing member 60, the effective distancebetween points 61 and 62 is substantially equal to the effectivedistance between points 61 and 64. The force imparted to each linkage4011 or 40b through the common vertical operating rod 46 is directlyproportional to the effective distance between the point 61 (at whichthe operating rod is connected to force-equalizing member 60) and thepoints 62 or 64, as the case may be, at which the particular'linkage isconnected to the force-equalizing member 60. By making these effectivedistances equal, we areable to distribute the force from thedownwardly-moving operating rod 46 substantially equally between the twolinkages, and thus substantially equally between the two movable valveelements 34.

The above-described equal speed relationship of the two movable valveelements 34 can beaffected by the presence of unequal frictionalopposing forces on the two valve elements, but we are able to largelyeliminate this effect by making the accelerating, or operating, forceslarge with respect to the frictional forces. Moreover, in our linkagethe main frictional opposing force is the friction betweenoperatingpiston 70 and cylinder 72; and this force, since it is associated withthe common operating piston 70, is common to both movable valve elements34 and does not contribute to any force inequalities capable ofaffecting the relative speeds of the valve elements.

EQUAL DISTRIBUTION OF OPENING CONTROL FORCES BETWEEN VALVE ELEMENTS Theforce-equalizing coupling 44 also enables us to achieve 1 closelysynchronized movement of the movable valve elements when they moveupwardly through their circuit breaker opening-initiating strokes.Recall in this regard that the operating force on the movable valveelements for this motion is derived from the gas pressure in tanks 14acting onbottom surfaces 83 of movable valve elements 34. Since thesevalve elements 34 have equal operating areas and since the pressures intanks 14 are equal (due to communication between the tanks), equaloperating forces are acting on the movable valve elements 34 tending todrive them upwardly. The restraining force opposing these operatingforces on the valve elements results primarily from high pressure gasabove main piston and the vented space beneath piston 70. Thisrestraining force is transmitted equally to the two movable valveelements 34 due to the force-equalizing coupling 44. When pressurizedgas is admitted to the space beneath piston 70 to initiate circuitbreaker opening, the net restraining force from the pressure on piston70 decreases as the gas pressure rapidly builds up. At any giveninstant, this net restraining force is transmitted substantially equallyto the movable valve elements 34 through force-equalizing coupling 44,and hence the two valve elements are subjected to substantially equalrestraining forces at any given instant. This relationship combined withthe equal operating forces on the two movable valve elements 34 resultsin their moving upwardly substantially simultaneously at substantiallythe same speed. The operating forces during this movement are largecompared to any frictional opposing forces, and hence these frictionalforces have little effect on the desired synchronization. The mainfrictional opposing force is the friction between main piston 70 andcylinder 72, and this force does not affect the equal speed relationshipbecause it is divided substantially equally between the two valveelements by the force-equalizing coupling 44. 1

The time required for a given movable control valve element 34 to movethrough its stroke will also be dependent upon the mass of the movablevalve element and the mass of the linkage between valve element 34 andthe forceequalizing member 60. But by making this substantially equalfor the two valve elements 34, we can minimize speed inequalities due tothis factor. Since the two valve elements are the same and the linkageportion 40a is substantially identical to 40b, it will be apparent thatthese masses are substantially equal.

COMPENSATION FOR ENCLOSURE SI-IIFIING. THERMAL EXPANSION, AND IMPRECISEASSEMBLY As pointed out hereinabove, there is a chance that circuitbreaker unit 11b will shift slightly with respect to unit 11a due towind loads or'unequal settling. If a conventional linkage were connectedbetween the control valves 30, this shifting of one circuit breaker unitwith respect to the other would tend to cause one or both of the movableelements 34 to move off its seat 37, assuming the circuit breaker isthen open, or off its other seat 39, assuming the circuit breaker isthen closed. Such movement of the control valve element 34 off its seat37 or 39 is highly undesirable since it would cause unintended operationof the circuit breaker. Similarly, if a conventional linkage wereconnected between the movable valve elements 34 and the effective lengthof the linkage changed due to thermal expansion or contraction, therewould be an undesirable tendency to move the movable control valveelements off their seat 37 or 39, as the case may be.

We are able to overcome these problems with our linkage 40 because it isable to compensate forthese changes in effective linkage length orposition of the circuit breaker units. In this respect, the floating,force-equalizing member 60 simply shifts in an appropriate direction toaccommodate the abovedescribed changes. For example, assume that circuitbreaker unit 11b of FIG. 1 shifts slightly ina direction away fromcircuit breaker unit 11a when the circuit breaker is in its closedposition of FIG. 2. The seating force on the movable valve elements 34,which is derived from fluid motor 48, would maintain the valve membersseated against the seat 39. But the tie 7 thought-of as being inactiveduring this period of compensation. The above-described counterclockwisemotion of forceequalizing member 60 against the downwardly acting forceon piston 70 and operating rod 46 produces a downward reaction on pivot62 which applies additional force to linkage 40a tending to hold thevalve member 34 of unit 11a on its seat 39.

A slight shift in the position of force-equalizing member 60 tocompensate for the above-described conditions has no substantial effecton the ability of coupling 44 to distribute forces equally between thetwo linkages40a and 40b. Despite this slight shift in position, theeffective distance between pints 61 and 62 remains substantially equalto the effective distance between points 61 and 64, and this enablescoupling 44 to retain its force-equalizing ability.

- Whether the linkages 40a, 40b have unequal effective lengths due tothermal causes, as above-described, or due to a lack of precision inassembling them, the force-equalizing coupling 40 will still functioninthe' same way to provide for precise location of the control valves 34on their seats. Similarly, whether the lack of precisene'ss in locatingthe circuit breaker units 11a and 11b is due-to the above-describedcauses (e.g., wind loads or settling) or is due to a failure of theassembler to locate the units exactly, the force-equalizing coupling 40will still function in the same way to provide for precise location ofthe control valves 34 on their seats.

THREE-CONTROL-VALVE EMBODIMENT or FIGS.

- tially identical circuit breaker units 11a, 11b and 11c electricallyconnected in series in powercirc uit25. Each of these circuit breakerunits comprises a metalltankj 14 at a high voltage with respect toground and an insulatingcolumn 15 supporting the tank and effectivelyisolating it from ground. The interrupter units within the tanks are thesame; as in FIGS. l--2.

Adjacent to metal tank 14 of the central circuit breaker unit 11c, thereis a casing 42 in which the force-equalizing coupling member 60 ismounted. The force-equalizing member 60 is connected to the controlvalves in the outer two circuitbreaker units 11a and 11b by linkages 40aand 40b which are substantially the same as linkages 40ojand 40b of FIGS1-2. The force equalizing member 60 is connected to the control valve ofthe center circuit breaker irnit 110 by a linkage 40c, best seen in FIG.5. This linkage comprises a valve actuating. rod 500', bellcrank 54c,and tie'link 55c. Bellcrank 54c is mounted on a stationary pivot 56c.Valve-actuating rod 500 is pivotally connected at one end to the movablevalve element (not shown) of the central circuit'breaker unit and at itsother end'to one arm of bellcrank 54:. The other end of bellcrank 54c ispivotally connected to a tie link 55c.

Linkage portions 40a, 40b, and 40c are'connected together by means offorceequalizing coupling 44. This coupling 44 comprises theforce-equalizing member 60, to which vertical operating rod 46 isconnected by means ofa universal joint 61. Referring to FIG. 6, thelinkage portions 40a, 40b, and 40c are connected to force-equalizingmember. 60 by universal joints 62, 64 and 65, respectively. These; threea universal joints respectively interconnect the force-equalizing member60 and tie links 55a, 55b and 550. t

Referring to FIG. 7, the universal joints 62, 64, and 65 may be thoughtof as being located at the corners of an equilateral triangle, indicatedby dotted lines 90, 91, 92. The universal joint 6i may be thought of asbeing located at the center of this triangle, spaced equidistantly fromthe centers of the three universal joints. The operation of theforce-equalizing coupling 44 is explained in greater detail hereinafter.

Vertical operating rod 46 extends between force-equalizing coupling 44and a fluid motor 48 at, its lower end. This fluid motor 48 issubstantially the same as fluid motor 48 of FIGS. 12 and is thereforenot explained in detail. A control valve 80 controls the operation offluid motor 48 in the same manner as described hereinabove with respectto FIGS. 1-2.

Circuit breaker opening is effected in essentially the same manner asexplained with respect to FIGS. 1-2. That is, high pressure gas isadmitted to the lower side of piston 70 to reduce the downward orrestraining force acting thereon. This allows the fluid pressure forceacting on the movable control valve elements 34 in the tanks topredominate and drive the movable valve elements 34 from theircircuit-breaker-closed position to their circuit-breaker-open position.

Circuit breaker closing is effected by venting the pressurized spacebeneath piston 70, thus allowing the piston to be driven downwardly fromits elevated circuit break open position. This motion is transmittedthrough force-equalizing member 60 and linkages 40a, 40b, and 40c to themovable control valve elements 34. This drives the movable valveelements 34 from their circuit breaker open positions to their circuitbreaker closed positions, thus effecting circuit breaker closing in themanner previously described.

We are able to achieve closely synchronized movement of the movablevalve elements 34 through their circuit breaker closing stroke becausewe distribute the operating force from fluid motor 48 substantiallyequally between the movable valve elements 34. This equal forcedistribution is made possible because the effective distances betweenthe central universal joint 61 and each of the three other universaljoints 62, 64, 65 are substantially equal. The force imparted to eachlinkage portion 40a, 40b, or 40c is directly proportional to theeffective distance between its universal joint and the central universaljoint 61; and by making these effective distances equal, we distributethe force from the downward moving operating rod substantially equallybetween the three linkages and thus substantially equally between thethree valve elements 34.

The force-equalizing coupling 44 also provides for closely Q.synchronized movement of the movable valve elements when they movethrough an opening initiating stroke. Recall that the force for suchopening initiating stroke is derived from the fluid pressure in tanks 14acting on movable valve elements 34. These forces. are substantiallyvequal, as explained with respect to FIGS. 1--2. The restraining forceopposing these operating forces on the valve elements results primarilyfrom high pressure gasabove main piston 70 and the vented space beneathpiston 70. When pressurizedgas is admitted to the space beneath piston70 to initiate circuit breaker opening, the net restraining force fromthe pressure on piston 70 decreases as the gas pressure builds up. Atany given instant, this net restraining force is transmittedsubstantially equally to the three valve elements 34 throughforce-equalizing coupling 44, and hence the three valve elements seesubstantially equal restraining forces at any given insta'nL'Thisrelationship com bined with the equal operating forces on the threemovable valve elements 34, results in their moving upwardlysubstantially simultaneously at substantially the same speed.

Although the three movable control valve elements 34 are identical, thelinkage portion 40c is shorter than linkages 40a and 40b, and this makesthe mass associated with the control valve 34 of the center unitslightly-less than the mass associated with the control valves of theother two units 11a and 1111. It has been found that this difference inthe eflective masses has only a small effect on synchronization of thethree valve elements. But we can reduce even this small effect byadding'a suitable weight (not shown) to the linkage 400 to make its masssubstantially the same as that of the other two linkages.

As pointed out hereinabove, there is a possibility that one circuitbreaker unit will shift slightly with respect to the others due to windsor unequal settling or the like. Also, the effective and scope of ourinvention.

v Q length of linkages 40a, 40b, and 400 may change slightly due tothermal expansion or contraction. Either of these conditions tends tocause undesired operation of the control valves. The linkages of FIGS.3-7 can compensate for either of these two conditions in substantiallythe same manner as described with respect to FIGS. 1-2 to therebyprevent undesired control valve operation. in this respect, the floatingforce-equalizingmember 60 simply shifts in an appropriate direction toaccommodate the abovedescribed changes. Despite the shift, the movablecontrol valve elements 34 remain in the seated position they are thenoccupying, being held in their circuitbreaker-closed position(corresponding to that of FIG. 2) by force from fluid motor 48. Theuniversal joints 62, 64, 65 between the three linkage portions and theforce-equalizing member and the universal joint 61 between the operatingrod and the force-equalizing member permit the force-equalizing member60 to shift in any direction needed to accommodate these changes. Forexample, assume that the tank 14 of the center circuit breaker unit lie,for, some reason, shifts slightly transverse to the plane of the paperin FIG. 3 away from the viewer. This would cause the force equalizingmember 60 to rock slightly in a counterclockwise direction about itsaxis X-X as seen in FIG. 6, concurrently lifting the operating rod 46slightly. This axis X-X extends through the centers of universal joints64 and 62. The universal joint 6! permits this rocking movement to occurwithout blockage from the operating rod 46; and universal joints 62, 64,65 permit this rocking movement to occur without blockage from thelinkages 40a, 40b, 400, respectively connected thereto.

Similarly, should the tank of circuit breaker unit 110 shift slightlyaway from the other tanks, there will be a tendency for linkage 40a torotate its crank 54a slightly counterclockwise. As viewed in FIG. 6,this rocks the force-equalizing member 60 slightly in a clockwisedirection about an axis Y-Y connecting the centers of universal joints64 and 65, concurrently lifting operating rod 46 slightly. The variousuniversal joints permit this movement of the force-equalizing member 60to occur without binding or blockage from the parts connnectedtherethrough to the force-equalizing member.

Similarly in the event that a shifting of circuit breaker unit llboccurs, crank 5411 will pivot slightly, rocking force equalizing member60 about axis Z-Z connecting universal joints 62 and 65. This providesthe same type of compensatory action as described hereinabove tomaintain the movable control valve elements 34 seated. Theforce-equalizing member 60 is, of course, able to rock suitablytofaccommodate any combination of these pivoting actions of cranks 54a,54b, and 54c.

GENERAL COMMENTS ln practicing our invention in its broader aspects,other forms of forceequalizing couplings can be used in place of thespecifically illustrated force-equalizing couplings 60. We preferhowever that the coupling be of a symmetrical design that provides forsubstantially equal force distribution to the control valves under bothstatic and'dynamic conditions.

While we have shown and described particular embodiments of ourinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made without departing from ourinvention in its broader aspects; and we, therefore, intend in theappended claims to cover all such changes and modifications as fallwithin the true spirit We claim: i

l. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosures at a high voltage with respectto ground;

b. means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure I relative to another; v

c. a plurality of circuit interrupting mearm respectively located withinsaid plurality of enclosures;

d. a plurality of control valves respectively located adjacent saidplurality of circuit interrupting means for initiating operation of theassociated interrupting means;

e. a force-equalizing member common to said control valves located in aposition between said control valves;

f. a plurality of linkage means respectively mechanically connectingsaid control valves'to said force-equalizing member;

g. an operating rod pivotally connected at one end to saidforce-equalizing member;

h. means for so mounting said force-equalizing member that its positioncan change slightly in' response to minor shifting of one of saidenclosures relative to another without imparting motion through saidlinkage means to any of said control valves;

i. means for actuating said operating rod comprising motive means forapplying an operating force to the other end of said operating rod, saidmotive means while inactive permitting minor longitudinal movement ofsaid operating rod in response to a slight change in the position ofsaid force-equalizing member;

j. said operating rod being pivotally connected to said forceequalizingmember at a central point spaced substantially equidistant from thepoints at which said linkage means are respectively connected. to saidforce-equalizing member; and

k. said force-equalizing member being a rigid member that during circuitbreaker operation maintains a fixed spacing between said points at whichsaid plurality of linkage means are respectively connected thereto.

2. The circuit breaker of claim 1 in which said forceequalizing memberacts to distribute a force applied to said other end of said operatingrod substantially equally between said control valves despite slightchanges in the position of said force-equalizing member in response toenclosure shiftmg.

3. The circuit breaker of claim 1 in combination with:

a. valve-operating means located at each enclosure for providing a forcefor operating the associated control valve against a restraining forceapplied to said other end of said operating rod; and

b. said force-equalizing member acting to distribute said restrainingforce substantially equally between said control valves, thereby topromote synchronized motion of said control valves. v

4. The circuit breaker of claim 3in which each of said valveoperatingmeans applies an operating force to said forceequalizing member which isdirected generally vertically at the points where said linkage means areconnected to said forceequalizing member, said operating forces actingin substantially the same vertical direction, said restraining forcebeing applied to said force-equalizing member in a vertically oppositedirection at the point where said operating rod is connected to saidforce-equalizing member.

5. A high voltage circuit breaker comprising:

a. a plurality. of spaced-apart enclosures at a high voltage withrespect to ground;

b. means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner. which permitsminor'shifting of one enclosure relative to another;

' c. a plurality of circuit interrupting means respectively locatedwithin said plurality of enclosures;

d. a plurality of control valves respectively located adjacent saidplurality of circuit interrupting means for initiating operation of theassociated interrupting means;

e. a force-equalizing member common to said control valves located in aposition between said control valves;

f. linkage means mechanically connecting said control valves to saidforce-equalizing member;

g. an operating rod mechanically connected at one end to saidforce-equalizing member;

h. means for so mounting said force-equalizing member that its positioncan change slightly in response to minor shifting of one of saidenclosures relative to another without k. said circuit breakercomprising three of said enclosures,

. said operating rod being connected to said force-equalizsaidforce-equalizing member beingconnected to said imparting motion throughsaid linkage-means to any of said control valves;

means for actuating said operating rod comprising motive means forapplying an operating forceto the other end of said operating rod, saidmotive means permitting minor longitudinal movement of said operatingrod in response to a slight change in the position of saidforce-equalizing member;

ing member at a central point spaced substantially equidistant from thepoints at which. said linkage means are connected to saidforce-equalizing member;

three of said interrupting means, three of said control 15 valves, andthree of said linkage means mechanically interconnecting said controlvalves and said force-equali2 ing member, I

three linkage means through three universal oints respectively locatedat the corners of a substantially equilateral reference triangle; and tin. said operating rod being connected to said force-equalizing memberat a central point on said triangle substantially equidistant from saidcorners. i

1 j. said operating rod being connected to said force-equaliz ing memberat a central point spaced substantially equidistant from the points atwhich said linkage means are connected to said force-equalizing member;and

it. said force-equalizingmember being a rigid member that during circuitbreaker operation maintains a fixed spacing between said points at whichsaid plurality of linkage means are respectively connected thereto. 10.The circuit breaker of claim 9 in which said forceequalizing member actsto distribute a force applied to said other end of said operating rodsubstantially equally between said control elements despite slightchanges in the position of said force-equalizing member in response to ashift of one enclosure relative to another.

6. The circuit breaker of claim 5 in which said operating rod isconnected to said force-equalizing member through a universal jointbetween the operating rod and said forceequalizing member. v

11. The circuit breaker of claim 1 in which: a. said control valves havepredetermined seats against which they respectively bear when saidcircuit breaker is 3 closed;

7. The circuit breaker of claim 5 in which:

a. said force-equalizing member is located at a level where the voltagewith respect to ground is high and substantially the same as that ofsaid enclosures when said circuit b. said motive means biases saidoperating rod in a direction to hold said control valves against theirrespective predetermined seats; and

c. while said circuit breaker is closed, any movement of said breaker isclosed- 35 f 1 one-equalizing member in response to shifting of one sald.opemung. rod i 'elecmca} Insulating enclosure which moves saidoperating rod against the bias i f s mom's s. at Substantially groan ofsaid motive means applies a reaction force to the coni an trol valve ofanother enclosure that acts in a direction to said lmmge means combmedwith said hold said control valve against its predetermined seat. memberextends between said enclosures in the high volt- 40 u A high voltage;circuit eak er comprising: of said and linkage means a. a plurality ofspaced-apart enclosures at a high voltage being partially of electricalinsulating material. with respfict to ground, is 2. g fi 2: d at levewhere b. means comprising a plurality of spaced-apart insulating i Zmgem 6 1s 0 a structures respectively supporting said enclosures in a ivoltage with respect ground hlgh m? manner which permits minor shiftingof one enclosure tially the same as that of said enclosures when saidcircuit relative to another breaker is closed; b. said operating rodpartially of electrical insulating g gz r mi gfifi ig ggfig rgrespecuvely $2 ,3 2:; ald motive means is f ground d. a plurality ofcontrol elements respectively located adc. said linkage means combinedwith v 'd three-equalizing i223:- 3 13232 332g ggg iggggfi lg fizggmember extends between said enclosures m the high voltf g p be R 3 l ofbeing partially of electrical insulat ng material. p 1 c e 9. A highvoltage circuit breaker comprising: f m a an d l l a. a plurality ofspaced-apart enclosures at a high voltage enigijggfffligfifi'Q y g s 531Comm 9 with respect to ground; I .7 l r; b. means comprising 'aplurality of spaced-apart insulating 8- l opel'atmg l'f y connected atone end to structures respectively supporting said enclosures in a saidf q g l i V manner which permits minor shifting of one enclosure 9*moummg sald f' l f l ti to h its position can change slightly'inresponse to minor shiftc. a plurality of circuit interrupting meansrespectivel of one of said enclosures relative to another withoutlocated within said plurality ofenclosures; mp g motion h ugh andlinkage means to any of d. a plurality of control elements respectivelylocated ad- Said col'lll'olelelllelllsi. I

jacent said plurality of circuit interrupting means for inmeans amalfng831d p f g p s motive itiating operation of the associated interruptingmeans; pp y g p force other end of e. a force-equalizing member commonto said control elesaid operating rod, said mot ve means permittingminor merits located in a position between said control elelongitudinalmovement of said operating rod in response merits; to a slight change inthe position of said force-equalizing f. a plurality of linkage meansrespectively mechanically member; I

connecting said control elements to said force-equalizing 3'. saidoperating rod being connected to said force-equalizmember; ing member ata central point spaced substantially I gain operating rod pivotallyconnected at one end to said equidistant from the points at which saidlinkage means force-equaliririg member; are connected to saidforceequalizing member;

it. said circuit breaker comprising three of said interrupting means,three of said control elements,and three of sd said linkage meansmechanically interconnecting said controi elements and saidforce-equalizing member;

l. said force-equalizing member being connected to said three linkagemeans through three universal joints respectively located at the cornersof asubstantially equilateral reference triangle; and

in. said operating rod being connected to said force-equalizing memberat a central point on said triangle substantially equidistant from saidcorners.

13. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosures at avhigh voltage with respectto ground;

b. means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures and permitting minor shifting ofone enclosure relative to another;

c. a plurality of circuit interrupting means respectively located withinsaid plurality of enclosures;

d. a plurality of control valves respectively located adjacent saidplurality of circuit interruptingmeans for initiating operation of theassociated interrupting means;

. a forceequalizing coupling "common to said control valves and locatedin a position between said control valves;

f. a plurality of linkage means respectively mechanically connectingsaid control valves to said force-equalizing coupling;

g. an operating rod pivotally connected at one end to saidforce-equalizing coupling;

. said force-equalizing coupling being so constructed that the positionof its parts can change slightly in response to minor shifting of one ofsaid enclosures relative to another without imparting motion throughsaid linkage means to any of said control valves;

. means for actuating said operating rod comprising motive means forapplying an operating force to the other end of said operating rod;

j. said motive means while inactive permitting minor longitudinalmovement of said operating rod in response to a slight change in theposition of the parts of said forceequalizing coupling; v

it. said linkage means and said force-equalizing coupling beingsubstantially free of lost motion that would allow said motive means tooperate without imparting motion to at least one of said control valves;and

I. said force-equalizing coupling comprising a substantially rigidforce-equalizing member connected to said linkage means at spaced pointsand "pivotally connected to said operating rod at a point between saidspaced points and maintaining a fixed spacing between said spacedpoints.

14. The circuit breaker of claim 13 in which said forceequalizingcoupling acts to distribute a force applied to said other end of saidoperating rod substantially equally between said control valves despiteslight changes in the position of the parts of said force-equalizingcoupling.-

15. The circuit breaker of claim 14 in combination with:

a. valve-operating means located at each enclosure for providing a forcefor operating the associated control valve against a restraining forceapplied to said other end of said operating rod; and

b. said force-equalizing coupling acting to distribute said restrainingforce substantially equally between said control valves, thereby topromote synchronized motion of said control valves.

16. A high voltage circuit breaker comprising:

a. a plurality of spaced-apart enclosuresat a high voltage with respectto ground;

b. means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure relative to another;

c. a plurality of circuit interrupting means respectively located withinsaid plurality of enclosures;

d. a plurality of control valves respectively located adjacent saidplurality of circuit interrupting means for initiating operation of theassociated interrupting means,

e. a force-equalizing member common to said control valves located in aposition between said control valves;

f. a plurality of linkage means respectively mechanically connectingsaid control valves to said forceequalizing member;

g. an operating rod mechanically connected at one end to saidforce-equalizing member;

h. means for so mounting said force-equalizing member that its positioncan change slightly in response to minor shifting of one of saidenclosuresrelative to another without imparting motion through saidlinkage means to any of said control valves;

. means for actuating said operating rod comprising motive means forapplying an operating force to the other end of said operating rod, saidmotive means permitting minor longitudinal movement of said operatingrod in response to a slight change in the position of saidforce-equalizing member;

. said operating rod being connected to said force-equalizing member ata central point spaced substantially equidistant from the points atwhich plurality of said linkage means are respectively connected to saidforceequalizing member,

. each of said enclosures containing high pressure fluid acting on theassociated control valves therein with substantially equal force andurging said control valves toward predetermined positions of circuitbreaker control;

. said motive means providing'a restraining force applied to said otherend of said operating rod which normally restrains said control valvesagainst movement toward said predetermined positions of circuit breakercontrol;

m. means for reducing said restraining force to permit said fluidpressure forces on said control valves to predominate and drive saidcontrol valves toward said predetermined positions; and

n. said force-equalizing member acting to distribute said restrainingforce at any given instant substantially equally between said controlvalves during their motion toward said predetermined positions ofcircuit breaker control.

17. A high voltage circuit breaker-comprising:

a. a plurality of spaced-apart enclosures at a high voltage with respectto ground;

b. means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure relative to another;

c. a plurality of circuit interrupting means respectively located withinsaid plurality of enclosures;

d. a plurality of control valves respectively located adjacent saidplurality of circuit interrupting means for initiating operation of theassociated interrupting means;

e. a force-equalizing member common to said control valves located in aposition between said control valves;

f. a plurality of linkage means respectively mechanically connectingsaid control 'valves to said force-equalizing member;

g. an operating rod mechanically connected at one end to saidforce-equalizing member;

h. means for so mounting said force-equalizing member that its positioncan change slightly in response to minor shifting of one of saidenclosures relative to another without control valves; 1

i. means for actuating said operating rod comprising motive means forapplying an operating force to the other end of said operating rod, saidmotive means permitting minor longitudinal movement of said operatingrod in response to a slight change in the position of saidforce-equalizing member;

Q said operating rod being connected to said force-equalizing member ata central point-spaced substantially equidistant from the points atwhich plurality of said linkage means are respectively connected to saidforceequalizing member;

k. said control valves having predetermined seats against which theyrespectively hear when said circuit breaker is closed;

i. said motive means biasing said operating rod in a direction l0 l6 Ito hold said control vsvas against their respective predetermined seats;and

m. while said circuit breaker is closed, any movement of

1. A high voltage circuit breaker comprising: a. a plurality ofspaced-apart enclosures at a high voltage with respect to ground; b.means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure relative to another; c. a plurality of circuitinterrupting means respectively located within said plurality ofenclosures; d. a plurality of control valves respectively locatedadjacent said plurality of circuit interrupting means for initiatingoperation of the associated interrupting means; e. a force-equalizingmember common to said control valves located in a position between saidcontrol valves; f. a plurality of linkage means respectivelymechanically connecting said control valves to said force-equalizingmember; g. an operating rod pivotally connected at one end to saidfoRce-equalizing member; h. means for so mounting said force-equalizingmember that its position can change slightly in response to minorshifting of one of said enclosures relative to another without impartingmotion through said linkage means to any of said control valves; i.means for actuating said operating rod comprising motive means forapplying an operating force to the other end of said operating rod, saidmotive means while inactive permitting minor longitudinal movement ofsaid operating rod in response to a slight change in the position ofsaid force-equalizing member; j. said operating rod being pivotallyconnected to said forceequalizing member at a central point spacedsubstantially equidistant from the points at which said linkage meansare respectively connected to said force-equalizing member; and k. saidforce-equalizing member being a rigid member that during circuit breakeroperation maintains a fixed spacing between said points at which saidplurality of linkage means are respectively connected thereto.
 2. Thecircuit breaker of claim 1 in which said force-equalizing member acts todistribute a force applied to said other end of said operating rodsubstantially equally between said control valves despite slight changesin the position of said force-equalizing member in response to enclosureshifting.
 3. The circuit breaker of claim 1 in combination with: a.valve-operating means located at each enclosure for providing a forcefor operating the associated control valve against a restraining forceapplied to said other end of said operating rod; and b. saidforce-equalizing member acting to distribute said restraining forcesubstantially equally between said control valves, thereby to promotesynchronized motion of said control valves.
 4. The circuit breaker ofclaim 3 in which each of said valve-operating means applies an operatingforce to said force-equalizing member which is directed generallyvertically at the points where said linkage means are connected to saidforce-equalizing member, said operating forces acting in substantiallythe same vertical direction, said restraining force being applied tosaid force-equalizing member in a vertically opposite direction at thepoint where said operating rod is connected to said force-equalizingmember.
 5. A high voltage circuit breaker comprising: a. a plurality ofspaced-apart enclosures at a high voltage with respect to ground; b.means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure relative to another; c. a plurality of circuitinterrupting means respectively located within said plurality ofenclosures; d. a plurality of control valves respectively locatedadjacent said plurality of circuit interrupting means for initiatingoperation of the associated interrupting means; e. a force-equalizingmember common to said control valves located in a position between saidcontrol valves; f. linkage means mechanically connecting said controlvalves to said force-equalizing member; g. an operating rod mechanicallyconnected at one end to said force-equalizing member; h. means for somounting said force-equalizing member that its position can changeslightly in response to minor shifting of one of said enclosuresrelative to another without imparting motion through said linkage meansto any of said control valves; i. means for actuating said operating rodcomprising motive means for applying an operating force to the other endof said operating rod, said motive means permitting minor longitudinalmovement of said operating rod in response to a slight change in theposition of said force-equalizing member; j. said operating rod beingconnected to said force-equalizing member at a central point spacedsubstantially equidistant from the points at which said linkage meansare connected to said force-equalizing memBer; k. said circuit breakercomprising three of said enclosures, three of said interrupting means,three of said control valves, and three of said linkage meansmechanically interconnecting said control valves and saidforce-equalizing member, l. said force-equalizing member being connectedto said three linkage means through three universal joints respectivelylocated at the corners of a substantially equilateral referencetriangle; and m. said operating rod being connected to saidforce-equalizing member at a central point on said trianglesubstantially equidistant from said corners.
 6. The circuit breaker ofclaim 5 in which said operating rod is connected to saidforce-equalizing member through a universal joint between the operatingrod and said force-equalizing member.
 7. The circuit breaker of claim 5in which: a. said force-equalizing member is located at a level wherethe voltage with respect to ground is high and substantially the same asthat of said enclosures when said circuit breaker is closed; b. saidoperating rod is partially of electrical insulating material and saidmotive means is at substantially ground potential; and c. said linkagemeans combined with said force-equalizing member extends between saidenclosures in the high voltage region of said circuit breaker, saidlinkage means being partially of electrical insulating material.
 8. Thecircuit breaker of claim 1 in which: a. said force-equalizing member islocated at a level where the voltage with respect to ground is high andsubstantially the same as that of said enclosures when said circuitbreaker is closed; b. said operating rod is partially of electricalinsulating material and said motive means is at substantially groundpotential; and c. said linkage means combined with said force-equalizingmember extends between said enclosures in the high voltage region ofsaid circuit breaker, said linkage means being partially of electricalinsulating material.
 9. A high voltage circuit breaker comprising: a. aplurality of spaced-apart enclosures at a high voltage with respect toground; b. means comprising a plurality of spaced-apart insulatingstructures respectively supporting said enclosures in a manner whichpermits minor shifting of one enclosure relative to another; c. aplurality of circuit interrupting means respectively located within saidplurality of enclosures; d. a plurality of control elements respectivelylocated adjacent said plurality of circuit interrupting means forinitiating operation of the associated interrupting means; e. aforce-equalizing member common to said control elements located in aposition between said control elements; f. a plurality of linkage meansrespectively mechanically connecting said control elements to saidforce-equalizing member; g. an operating rod pivotally connected at oneend to said force-equalizing member; h. means for so mounting saidforce-equalizing member that its position can change slightly inresponse to minor shifting of one of said enclosures relative to anotherwithout imparting motion through said linkage means to any of saidcontrol elements; i. means for actuating said operating rod comprisingmotive means for applying an or operating force to the other end of saidoperating rod, said motive means while inactive permitting minorlongitudinal movement of said operating rod in response to a slightchange in the position of said force-equalizing member; j. saidoperating rod being connected to said force-equalizing member at acentral point spaced substantially equidistant from the points at whichsaid linkage means are connected to said force-equalizing member; and k.said force-equalizing member being a rigid member that during circuitbreaker operation maintains a fixed spacing between said points at whichsaid plurality of linkage means are respectively connected thereto. 10.The circuit breaker of claim 9 in which said foRce-equalizing memberacts to distribute a force applied to said other end of said operatingrod substantially equally between said control elements despite slightchanges in the position of said force-equalizing member in response to ashift of one enclosure relative to another.
 11. The circuit breaker ofclaim 1 in which: a. said control valves have predetermined seatsagainst which they respectively bear when said circuit breaker isclosed; b. said motive means biases said operating rod in a direction tohold said control valves against their respective predetermined seats;and c. while said circuit breaker is closed, any movement of saidforce-equalizing member in response to shifting of one enclosure whichmoves said operating rod against the bias of said motive means applies areaction force to the control valve of another enclosure that acts in adirection to hold said control valve against its predetermined seat. 12.A high voltage circuit breaker comprising: a. a plurality ofspaced-apart enclosures at a high voltage with respect to ground; b.means comprising a plurality of spaced-apart insulating structuresrespectively supporting said enclosures in a manner which permits minorshifting of one enclosure relative to another; c. a plurality of circuitinterrupting means respectively located within said plurality ofenclosures; d. a plurality of control elements respectively locatedadjacent said plurality of circuit interrupting means for initiatingoperation of the associated interrupting means; e. a force-equalizingmember common to said control elements located in a position betweensaid control elements; f. linkage means mechanically connecting saidcontrol elements to said force-equalizing member; g. an operating rodmechanically connected at one end to said force-equalizing member; h.means for so mounting said force-equalizing member that its position canchange slightly in response to minor shifting of one of said enclosuresrelative to another without imparting motion through said linkage meansto any of said control elements; i. means for actuating said operatingrod comprising motive means for applying an operating force to the otherend of said operating rod, said motive means permitting minorlongitudinal movement of said operating rod in response to a slightchange in the position of said force-equalizing member; j. saidoperating rod being connected to said force-equalizing member at acentral point spaced substantially equidistant from the points at whichsaid linkage means are connected to said force-equalizing member; k.said circuit breaker comprising three of said interrupting means, threeof said control elements, and three of sd said linkage meansmechanically interconnecting said control elements and saidforce-equalizing member; l. said force-equalizing member being connectedto said three linkage means through three universal joints respectivelylocated at the corners of a substantially equilateral referencetriangle; and m. said operating rod being connected to saidforce-equalizing member at a central point on said trianglesubstantially equidistant from said corners.
 13. A high voltage circuitbreaker comprising: a. a plurality of spaced-apart enclosures at a highvoltage with respect to ground; b. means comprising a plurality ofspaced-apart insulating structures respectively supporting saidenclosures and permitting minor shifting of one enclosure relative toanother; c. a plurality of circuit interrupting means respectivelylocated within said plurality of enclosures; d. a plurality of controlvalves respectively located adjacent said plurality of circuitinterrupting means for initiating operation of the associatedinterrupting means; e. a force-equalizing coupling common to saidcontrol valves and located in a position between said control valves; f.a plurality of linkage means respectively mechanically connecting Saidcontrol valves to said force-equalizing coupling; g. an operating rodpivotally connected at one end to said force-equalizing coupling; h.said force-equalizing coupling being so constructed that the position ofits parts can change slightly in response to minor shifting of one ofsaid enclosures relative to another without imparting motion throughsaid linkage means to any of said control valves; i. means for actuatingsaid operating rod comprising motive means for applying an operatingforce to the other end of said operating rod; j. said motive means whileinactive permitting minor longitudinal movement of said operating rod inresponse to a slight change in the position of the parts of saidforce-equalizing coupling; k. said linkage means and saidforce-equalizing coupling being substantially free of lost motion thatwould allow said motive means to operate without imparting motion to atleast one of said control valves; and l. said force-equalizing couplingcomprising a substantially rigid force-equalizing member connected tosaid linkage means at spaced points and pivotally connected to saidoperating rod at a point between said spaced points and maintaining afixed spacing between said spaced points.
 14. The circuit breaker ofclaim 13 in which said force-equalizing coupling acts to distribute aforce applied to said other end of said operating rod substantiallyequally between said control valves despite slight changes in theposition of the parts of said force-equalizing coupling.
 15. The circuitbreaker of claim 14 in combination with: a. valve-operating meanslocated at each enclosure for providing a force for operating theassociated control valve against a restraining force applied to saidother end of said operating rod; and b. said force-equalizing couplingacting to distribute said restraining force substantially equallybetween said control valves, thereby to promote synchronized motion ofsaid control valves.
 16. A high voltage circuit breaker comprising: a. aplurality of spaced-apart enclosures at a high voltage with respect toground; b. means comprising a plurality of spaced-apart insulatingstructures respectively supporting said enclosures in a manner whichpermits minor shifting of one enclosure relative to another; c. aplurality of circuit interrupting means respectively located within saidplurality of enclosures; d. a plurality of control valves respectivelylocated adjacent said plurality of circuit interrupting means forinitiating operation of the associated interrupting means, e. aforce-equalizing member common to said control valves located in aposition between said control valves; f. a plurality of linkage meansrespectively mechanically connecting said control valves to saidforce-equalizing member; g. an operating rod mechanically connected atone end to said force-equalizing member; h. means for so mounting saidforce-equalizing member that its position can change slightly inresponse to minor shifting of one of said enclosures relative to anotherwithout imparting motion through said linkage means to any of saidcontrol valves; i. means for actuating said operating rod comprisingmotive means for applying an operating force to the other end of saidoperating rod, said motive means permitting minor longitudinal movementof said operating rod in response to a slight change in the position ofsaid force-equalizing member; j. said operating rod being connected tosaid force-equalizing member at a central point spaced substantiallyequidistant from the points at which plurality of said linkage means arerespectively connected to said force-equalizing member; k. each of saidenclosures containing high pressure fluid acting on the associatedcontrol valves therein with substantially equal force and urging saidcontrol valves toward predetermined positions of circuit breakercontrol; l. said motive means providing a restraining foRce applied tosaid other end of said operating rod which normally restrains saidcontrol valves against movement toward said predetermined positions ofcircuit breaker control; m. means for reducing said restraining force topermit said fluid pressure forces on said control valves to predominateand drive said control valves toward said predetermined positions; andn. said force-equalizing member acting to distribute said restrainingforce at any given instant substantially equally between said controlvalves during their motion toward said predetermined positions ofcircuit breaker control.
 17. A high voltage circuit breaker comprising:a. a plurality of spaced-apart enclosures at a high voltage with respectto ground; b. means comprising a plurality of spaced-apart insulatingstructures respectively supporting said enclosures in a manner whichpermits minor shifting of one enclosure relative to another; c. aplurality of circuit interrupting means respectively located within saidplurality of enclosures; d. a plurality of control valves respectivelylocated adjacent said plurality of circuit interrupting means forinitiating operation of the associated interrupting means; e. aforce-equalizing member common to said control valves located in aposition between said control valves; f. a plurality of linkage meansrespectively mechanically connecting said control valves to saidforce-equalizing member; g. an operating rod mechanically connected atone end to said force-equalizing member; h. means for so mounting saidforce-equalizing member that its position can change slightly inresponse to minor shifting of one of said enclosures relative to anotherwithout control valves; i. means for actuating said operating rodcomprising motive means for applying an operating force to the other endof said operating rod, said motive means permitting minor longitudinalmovement of said operating rod in response to a slight change in theposition of said force-equalizing member; j. said operating rod beingconnected to said force-equalizing member at a central point spacedsubstantially equidistant from the points at which plurality of saidlinkage means are respectively connected to said force-equalizingmember; k. said control valves having predetermined seats against whichthey respectively bear when said circuit breaker is closed; l. saidmotive means biasing said operating rod in a direction to hold saidcontrol valves against their respective predetermined seats; and m.while said circuit breaker is closed, any movement of saidforce-equalizing member in response to shifting of one enclosure whichmoves said operating rod against the bias of said motive means applyinga reaction force to the control valve of another enclosure that acts ina direction to hold said control valve against its predetermined seat.